Patent GB-481235-A (GB)
Title: A process for the desulphurisation of hydrocarbons
IPC: C10K1/08
Filed: 1937-04-07
Abstract: Mixtures of hydrocarbons are desulphurized by treatment with a substantially anhydrous alkali hydroxide solution in a non-acidic hydroxy organic solvent, or with an alkali alcoholate, and then with an aqueous solution of an alkali hydroxide.  The treatment may be preceded by treatment with other desulphurizing agents e.g. tripotassium phosphate, triethanolamine, <PICT:0481235/III/1> aqueous sodium hydrate, or sulphuric acid.  The process is preferably carried out with the hydrocarbons in the liquid state at temperatures between 10 and 30 DEG  C. but may be effected by bubbling the hydrocarbon vapours through the alkali solutions. The substantially anhydrous alkali hydroxide solution should contain less than 10 per cent of water and may be prepared by dissolving the alkali in primary, secondary or tertiary alcohols, glycols, glycerine, hydramines or hydroxy ethers.  In the plant shown diagrammatically on the drawing, hydrocarbons pass by a line 1 into a mixer 2 where they are mixed with an aqueous solution of a reagent such as tripotassium phosphate. The mixture is transferred to a settler 5 from which the treated hydrocarbons pass to a vessel 8 in which the treatment is repeated. The spent treating solution from the vessels 5, 8 is passed through a heating coil 11 in a furnace 12 to a regenerator 14 in which it is treated with steam, the regenerated solution being recirculated by a pump 17.  The hydrocarbons from the vessel 8 are treated with aqueous sodium hydroxide in a vessel 21 and then pass through a mixer 23 together with a solution of alcoholic potassium hydroxide circulated by a pump 24.  Normally an excess of the alcoholic solution is used so that the resulting mixture separates into two layers in the separator 27, viz. a layer of alcoholic potassium hydroxide, which is recirculated by pump 24, and an upper layer of hydrocarbons, which are transferred to a vessel 31 in which they are treated with aqueous sodium hydroxide.  Alternatively, an amount of alcoholic potassium hydroxide is dissolved in the hydrocarbons in the mixer 23 which is insufficient to cause separation of two liquid phases in the separator 27, in which case the resulting mixture is conducted through lines 36, 30 directly to the vessel 31, when the reaction products between the alcoholic potassium hydroxide and the sulphur compounds are washed out from the hydrocarbons.ALSO:<PICT:0481235/IV/1> Mixtures of hydrocarbons are desulphurized by treatment with a substantially anhydrous alkali hydroxide solution in a non-acidic hydroxy organic solvent, or with an alkali alcoholate, and then with an aqueous solution of an alkali hydroxide.  The treatment may be preceded by treatment with other desulphurizing agents, e.g. tripotassium phosphate, triethanolamine, aqueous sodium hydrate, or sulphuric acid.  The process is preferably carried out with the hydrocarbons in the liquid state at temperatures between 10 and 30 DEG  C., but may be effected by bubbling the hydrocarbon vapours through the alkali solutions.  The substantially anhydrous alkali hydroxide solution should contain less than 10 per cent of water and may be prepared by dissolving the alkali in primary, secondary or tertiary alcohols, glycols, glycerine, hydramines or hydroxy ethers.  In the plant shown diagrammatically in the Figure, hydrocarbons pass by a line 1 into a mixer 2 where they are mixed with an aqueous solution of a reagent such as tri-potassium phosphate.  The mixture is transferred to a settler 5 from which the treated hydrocarbons pass to a vessel 8 in which the treatment is repeated.  The spent treating solution from the vessels 5, 8 is passed through a heating coil 11 in a furnace 12 to a regenerator 14 in which it is treated with steam, the regenerated solution being recirculated by a pump 17.  The hydrocarbons from the vessel 8 are treated with aqueous sodium hydroxide in a vessel 21 and then pass through a mixer 23 together with a solution of alcoholic potassium hydroxide circulated by a pump 24.  Normally, an excess of the alcoholic solution is used so that the resulting mixture separates into two layers in the separator 27, viz.: a layer of alcoholic potassium hydroxide, which is recirculated by pump 24, and an upper layer of hydrocarbons, which are transferred to a vessel 31 in which they are treated with aqueous sodium hydroxide.  Alternatively, an amount of alcoholic potassium hydroxide is dissolved in the hydrocarbons in the mixer 23 which is insufficient to cause separation of two liquid phases in the separator 27, in which case the resulting mixture is conducted through lines 36, 30 directly to the vessel 31, when the reaction products between the alcoholic potassium hydroxide and the sulphur compounds are washed out from the hydrocarbons.